Safety, Efficacy, and Persistence of Long-Term Mirabegron Treatment for Overactive Bladder in the Daily Clinical Setting: Interim (1-Year) Report from a Japanese Post-Marketing Surveillance Study.

OBJECTIVES: To report interim 1-year results from a 3-year surveillance study evaluating safety, efficacy, and persistence of long-term mirabegron for overactive bladder (OAB).

METHODS: Patients starting treatment with mirabegron for urinary urgency, daytime frequency, and urgency incontinence associated with OAB were registered and followed up for 3 years. Data were collected on adverse drug reactions (ADR), changes in OAB symptoms, changes in Overactive Bladder Symptom Score (OABSS), and treatment discontinuations. Treatment persistence rates were calculated by Kaplan-Meier analysis.

RESULTS: Eighty-one ADR were observed in 72/1139 patients (6.3%) through 1 year of mirabegron treatment, with the incidence highest during the first month. No significant change in residual urine volume was observed at any observation point up to 1 year of mirabegron treatment. Mirabegron was deemed "effective" in 883/1091 patients (80.9%) at 1 year/discontinuation. Total OABSS was decreased with statistical significance at 3 months, 6 months, and 1 year, or at discontinuation (P < 0.001 at each time point). Kaplan-Meier treatment persistence rates were 84.8% at 3 months, 77.6% at 6 months, and 66.0% at 1 year. Treatment persistence rates were similar for male and female patients but significantly higher for patients aged ≥65 years (67.3%; n = 908) compared with those aged <65 years (59.8%; n = 231; log-rank test: P = 0.032).

CONCLUSIONS: Long-term OAB treatment with mirabegron was well-tolerated, with effectiveness maintained through 1 year. Mirabegron treatment persistence was higher than has been previously reported, and was greater in patients aged ≥65 years compared with those aged <65 years.